Conventionally, a viscous fluid supply device, for example, has a housing and a movable member movably arranged inside the housing, and is configured to, by increasing pressure in an air chamber using a pressure adjusting device, supply the viscous fluid filled between the housing and the movable member from an ejection nozzle.
Further, the viscous fluid supplied by the viscous fluid supply device is depleted every time various work is performed with respect to a circuit board (for example, work of forming solder deposits or the like on the surface of the circuit board, and work of mounting electronic components on the circuit board). Therefore, when using such a viscous fluid supply device, it is necessary to perform work to refill the viscous fluid supply device with viscous fluid, and to improve the work efficiency of performing work with respect to the circuit board, it is necessary to know the remaining amount of viscous fluid in the viscous fluid supply device.
As an example of a viscous fluid supply device that takes account of this, for example, the device disclosed in patent literature 1 is known. The solder supply device disclosed in patent literature 1 includes a solder cup that stores viscous solder, and a supply nozzle that enters inside the solder cup; by supplying air to the space formed between the solder cup and an outer tube, the solder cup is moved, thereby supplying the solder in the solder cup.
Further, the solder supply device disclosed in patent literature 1 includes a first photoelectric sensor for detecting a position of a solder cup that is empty of solder paste being used as a viscous fluid inside the solder cup, and a second photoelectric sensor for detecting a position of a solder cup that has a specified remaining amount of solder paste. The first photoelectric sensor and the second photoelectric sensor are configured to detect the presence of a target item by receiving light that is reflected by a target object (solder cup), the light being laser light emitted in a specified direction. The solder supply device recognizes the remaining amount of solder paste by detecting the movement distance of the solder cup based on the detection results of the first photoelectric sensor and the second photoelectric sensor, and reports the amount by displaying it on a panel or the like.